Tag Archives: humuhumu­nukunukuapuaa

The fish with a piglike nose apparently now flourishing

Published April 18, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
The wedgetail triggerfish can brace itself inside a hole in the reef, safe from predators, using spines. One species, the humu-humunukunukuapuaa, is the official state fish. ©2016 Susan Scott

The wedgetail triggerfish can brace itself inside a hole in the reef, safe from predators, using spines. One species, the humu-humunukunukuapuaa, is the official state fish. ©2016 Susan Scott

Because it seems that wedgetail triggerfish are having a banner year, last week I swam in a straight line and counted them. In only a few minutes, I saw 12.

I know I wasn’t counting the same fish over and over because I was snorkeling in 4 to 5 feet of water, and my close passing caused each fish to dive into a bunker. And there they stayed, locked and loaded. Once a triggerfish is in a hole, it really is locked. Triggerfish prefer spaces so small the fish can barely squeeze their bodies inside. Tough, sandpapery skin allows triggerfish to scrape against coral rock without harm.

Once in, the fish raises from its back a long hard spine that sticks into the cave’s ceiling. A smaller spine behind fits into a groove of the larger, bracing it upright. To anchor its lower half, the triggerfish extends a bone on its belly. It’s the fish version of jamming a chair under a doorknob.

Triggerfish wedge themselves in so securely that one could pull the fish out only by reaching in and depressing the second, bracing spine.

 

But don’t try it. Triggerfish are also loaded. Their weapons are sharp chisel-like teeth, eight in an outer row and six more in an inner row that shore up the outer.

Nor should a snorkeler or diver try getting a close look at a triggerfish’s egg mass. The mother will charge, and sometimes bite, anything threatening her clutch.

In other fish families that lay eggs on the ocean floor, such as damselfish and blennies, males guard the eggs. But triggerfish males have harems, which leaves them little time for baby-sitting. The male patrols his territory of females, chasing away interloping males with mating on their minds. That leaves each female in the harem responsible for safeguarding her own brood.

All this chasing and charging is exhausting for both sexes, but triggerfish romance is a one-day affair. Females lay their eggs at dawn, the male immediately fertilizes them and their tiny offspring hatch that night.

Of the world’s 37 species of triggerfish, all ranging throughout the Pacific and Indian oceans, Hawaii hosts 10. One, however, is special here because of a 1984 election for Hawaii’s state fish. The multihued wedgetail triggerfish won, partly because it has a cute Hawaiian name in a cute Hawaii song. In “My Little Grass Shack” the humuhumunukunukuapuaa go swimming by. With all their darting and ducking, wedgetail triggerfish remind me of kids playing soldiers while wrapped in their grandma’s patchwork quilts. Whatever the cause of this fish bloom right now, I’m glad of it. Dozens of humuhumunukunukuapuaa brighten any day.

Sharp teeth, aggressive ways turn triggerfish into a terror

The titan triggerfish defends itself with sharp teeth. ©2013 Susan Scott

The titan triggerfish defends itself with sharp teeth. ©2013 Susan Scott

TAHAA, FRENCH POLYNESIA » Here in the Society Islands, I swim with black-tipped reef sharks, free-dive on giant moray eels and float inches above venomous, spine-waving sea urchins, all without worry.But when I come face to face with a titan triggerfish, I pay attention. Snorkelers and divers do not mess with these mamas.

Triggerfish get their name from a fin on the back that the fish can raise and lock in place with a shorter second fin.At the first sign of danger or to bed down for the night, the triggerfish ducks into a hole in the reef, raises its trigger and locks in.

Years ago a triggerfish researcher told me a memorable story.Wondering how strong the spines were on a reef triggerfish (known in Hawaii as the humuhumu­nukunukuapuaa) and how long the fish would keep its trigger up when threatened, he reached into the hole, grasped the body and pulled. And pulled.The fish died locked in.

The researcher did his experimental tugging from the tail end because a triggerfish’s other defense is a pair of strong jaws and 14 chisel-sharp teeth.

Triggerfish use their formidable teeth to crunch up snails, crabs and sea urchins. Females also use their teeth to defend their fertilized eggs.

Among damselfish, blennies and some other reef fish, the males defend nests.Male triggerfish, however, have harems, making egg protection at each site impossible.

Offspring defense is therefore left to the females, which, like all mothers, take the job seriously.Get close to an egg patch, and female triggerfish of all species will charge and bite.

Such high security requires high energy, but guard duty doesn’t last long.Female triggerfish lay eggs and males fertilize them at dawn. The larvae hatch the next night.

The well-named titan triggerfish, not found in Hawaii, grows up to 30 inches long.This beefy giant is more than twice the size of Hawaii’s common triggerfish.

It’s easy for snorkelers and divers to know where a triggerfish’s eggs lay.Get too close and a titan triggerfish female will make a high-speed bluff charge or two before she bites a leg or attacks a camera.

After coming face to face with the teeth-baring titan triggerfish in this photo, I heeded her unmistakable message. I left the area to snorkel with safer reef residents, sharks, eels and urchins.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2013 Susan Scott